89
Monobloc Outdoor Unit Installation Manual
Check Code
Diagnostic functional operation
Determination and action
Alarm [P344]
Curr
ent Alarm [P346] to [P349]
Past Alarm [P350] to [P354]
Operational Cause
Unit Status
Automatic
Reset
100
10
Inverter discharge temperature
(TD) sensor failure
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error becomes
definite after retrying operation 4 times.
1. Check discharge temperature sensor (TD)
102
11
Inverter air exchanger
temperature (TE) sensor failure
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error becomes
definite after retrying operation 4 times.
1. Check temperature sensor (TE)
103
12
Inverter liquid temperature (TL)
sensor failure
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error becomes
definite after retrying operation 4 times.
1. Check temperature sensor (TL)
104
13
Inverter TO sensor failure
Continue
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit.
Unit operation continues in backup mode. TO sensor value fixed to 30°C in cooling,
10°C in heating. Backup mode is cancelled when any other value is detected by TO
sensor.
1. Check outside temperature sensor (TO)
108
14
Inverter Suction Temperature
(TS)
Sensor failure
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error becomes
definite after retrying operation 4 times.
1. Check suction temperature sensor (TS)
109
15
Inverter heatsink temperature
failure
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error becomes
definite after retrying operation 8 times.
1. Check correct fan operation
111
16
Inverter TE & TS sensors
wrongly connected
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error becomes
definite after retrying operation 4 times.
1. Check temperature sensor (TE, TS)
119
17
Inverter suction pressure (PS)
sensor failure
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error becomes
definite after retrying operation for 2 times for disconnection detection and 4 times for
high pressure.
1. Check suction pressure sensor (LP)
-
20
Loss of communication with RC
Continue
X
Alarm reset when a new message is received from the RC
1.
Check RC connections (RC & Monobloc outdoor unit)
-
21
Loss of communication with
inverter
Compressor stop
X
Alarm reset when a new message is received from the inverter.
1.
Check connections between inverter PCB & NHC board
221
22
Loss of communication
between inverter PCB’s
Compressor stop
O
Alarm caused by delay in communication. Alarm reset by resetting the power supply to
the Monobloc outdoor unit.
-
23
Loss of communication with
follower units
Header continues
X
Automatic reset when communication between follower units is restored.
-
24
Loss of communication with
header unit
Stop
X
Automatic reset when communication with the header unit is restored.
-
31
Safety input
Unit stop OR heat
stop OR cool stop
X
Automatic reset when the safety input is closed.
-
32
Flow switch failure
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error becomes
definite after retrying operation for 5 times.
1. Check flow switch operation / connections
2. Check / clean water filter
228
33
Inverter high pressure release
failure
Compressor stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Error detected
when discharge pressure exceeds HP switch limit pressure.
1. Check of outdoor fan operation.
2. Check motor error of outdoor fan.
3. Check clogging of outdoor PMV.
4. Check clogging of heat exchanger.
5. Check for re-cycling of air around air heat exchanger
-
50
Exchanger freeze protection on
water temperature (in cooling)
Stop
X
Automatic reset when EWT or LWT is ≥4°C. Alarm is activated during cooling mode or
a defrost operation and when EWT or LWT < 4°C
Cooler heater is energized while the alarm is active. Water pump is forced to run.
1. Check water flow rate
2. Check water pressure drop
3. Check EWT sensor
4. Check LWT sensor
-
51
Exchanger freeze protection
on refrigerant temperature (in
cooling)
Stop
O
Alarm reset by resetting the power supply to the Monobloc outdoor unit. Energized
Cooler Heater while alarm is active.
Force pump to run until alarm reset kind becomes manual.
Error becomes definite after retrying operation more than 12 occurrences within a 2
hours period
1. Check TR, TD, TS & BP sensors
2. Check PMV is operating correctly
3. Check refrigerant circuit for leaks
4. Check refrigerant pipes are not damaged
